Syringe exchange programs (SEPs) have proven to be among the most controversial public health HIV prevention efforts, despite demonstrated scientific evidence of their effectiveness in lowering risk and infection among injection drug users. Community opposition to SEPs in some locales has been sufficient to block initiation of SEPs and, elsewhere, to shut down existing programs. Given the demonstrated effectiveness of SEPs as an HIV prevention method, this study seeks to understand why they have not received universal support. The proposed study will examine the social ecology of minority communities in Springfield, Massachusetts, a city that lacks pharmacy access to sterile syringes and needle exchange, to understand the social and physical dynamics of HIV risk. Between 1997 and 2001, Springfield moved from having the 49 th highest AIDS rate in the nation (among metropolitan statistical areas) to the 1lth highest AIDS rate. Community-based organizations in Springfield have historically failed to support needle exchange as an HIV prevention measure, believing that it is analogous to "giving a cocktail glass to an alcoholic." By directing our attention to community-based organizations we seek to identify contextual environmental factors that promote or impede the effectiveness of HIV prevention interventions for drug-using populations. Existing studies of the implementation of needle exchange fail to account for the institutional factors that facilitate or impede such programs, including the support or opposition of key community organizations. We propose to examine the reasons for grassroots mobilization against needle exchange in Springfield through in-depth interviews with community organization staff and other stakeholders. We further propose a limited community survey to determine the degree to which community organizations represent community attitudes, and vice versa. The specific aims of the proposed study are as follows: 1. To understand the social, historical and political dynamics of community opposition to needle exchange in Springfield, Massachusetts; 2. To explore the role of community institutions in supporting or opposing legal needle exchange as an HIV prevention measure; 3. To examine community opinions on needle exchange and other aspects of IDU-targeted HIV prevention through quantitative surveys.